I think you can use your votes however you want, including on yourself. I also think other people can use their votes however they want, including downvoting the posts you upvote. That’s how the system is designed.
And I think that it’s also OK to point out undesirable or potentially destructive behavior while understanding that everyone can use their stake however they want. That’s what being “social” means - that there may be consequences for our actions, based on the subjective opinions and values of other people in our community and with whom we interact.
It’s a complex and dynamic system.
So, sure...I support the concept of self-voting. It would be absurd to be opposed to it, since the entire platform is based on how much you are invested and based on using that stake to influence behavior/outcomes/rewards in this system.